Longitudinal Doppler sonographic measurements of vascular impedance in the central and peripheral spiral arteries throughout pregnancy

Hsieh, Yao Yuan; Chang, Chih-Han; Tsai, Horng‐Der; Lee, Chien-Chung; Tsai, Chang‐Hai

doi:10.1002/(sici)1097-0096(200002)28:2<78::aid-jcu4>3.0.co;2-x

Cited by 16 publications

(24 citation statements)

References 11 publications

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“…Equally, both the resistance index and the pulsatility index have been reported to be lower in spiral arteries in the central region of the placental bed during the second trimester than in peripheral regions [54], and these findings correlate closely with the normal pattern of extravillous trophoblast invasion [55]. However, a more recent study found no difference between the two regions [56]. Any reduction in resistance will increase flow, and potentially lead to further dilation of the artery through increased shear stress and nitric oxide-mediated pathways in a feed-forward fashion.…”

Section: Physiological Consequences Of Spiral Arterial Conversionmentioning

confidence: 93%

Rheological and Physiological Consequences of Conversion of the Maternal Spiral Arteries for Uteroplacental Blood Flow during Human Pregnancy

et al. 2009

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Physiological conversion of the maternal spiral arteries is key to a successful human pregnancy. It involves loss of smooth muscle and the elastic lamina from the vessel wall as far as the inner third of the myometrium, and is associated with a 5–10-fold dilation at the vessel mouth. Failure of conversion accompanies common complications of pregnancy, such as early-onset preeclampsia and fetal growth restriction. Here, we model the effects of terminal dilation on inflow of blood into the placental intervillous space at term, using dimensions in the literature derived from three-dimensional reconstructions. We observe that dilation slows the rate of flow from 2 to 3 m/s in the non-dilated part of an artery of 0.4–0.5 mm diameter to approximately 10 cm/s at the 2.5 mm diameter mouth, depending on the exact radius and viscosity. This rate predicts a transit time through the intervillous space of approximately 25 s, which matches observed times closely. The model shows that in the absence of conversion blood will enter the intervillous space as a turbulent jet at rates of 1–2 m/s. We speculate that the high momentum will damage villous architecture, rupturing anchoring villi and creating echogenic cystic lesions as evidenced by ultrasound. The retention of smooth muscle will also increase the risk of spontaneous vasoconstriction and ischaemia–reperfusion injury, generating oxidative stress. Dilation has a surprisingly modest impact on total blood flow, and so we suggest the placental pathology associated with deficient conversion is dominated by rheological consequences rather than chronic hypoxia.

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Section: Physiological Consequences Of Spiral Arterial Conversionmentioning

confidence: 93%

Rheological and Physiological Consequences of Conversion of the Maternal Spiral Arteries for Uteroplacental Blood Flow during Human Pregnancy

et al. 2009

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“…1309 SpA were measured during the rst trimester in 778 women. Five studies performed assessment during the second trimester, capturing 1011 SpA measurements in 456 women (2,9,30,32,33). Two studies published 593 SpA Doppler PI measurements during the third trimester measured in 209 women (30,32).…”

Section: Pulsatility Indexmentioning

confidence: 99%

“…Spiral arteries located in the central part of the placental bed, versus those located at its periphery Differences between central and peripheral SpA Doppler indices during the second trimester were investigated in two studies (9,32). (Figure 7).…”

Section: Pulsatility Indexmentioning

confidence: 99%

Spiral artery blood flow during pregnancy: a systematic review and meta-analysis.

Schiffer

Evers

Haas

et al. 2020

Preprint

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Abstract Background: Downstream remodeling of the spiral arteries (SpA) decreases utero-placental resistance drastically, allowing sustained and increased blood flow to the placenta at all circumstances. We systematically evaluated available reports to visualize adaptation of spiral arteries throughout pregnancy by ultra-sonographic measurements and evaluated when this process is completed.Methods: A systematic review and meta-analysis of spiral artery flow (pulsatility index (PI), resistance index (RI) and peak systolic velocity (PSV)) was performed. English articles were obtained from Pubmed, EMBASE and Cochrane Library and included articles were assessed on quality and risk of bias. Weighted means of Doppler indices were calculated using a random-effects model. Results: In healthy pregnancies, PI and RI decreased from 0.80 (95% CI: 0.70-0.89) and 0.50 (95% CI: 0.47-0.54) in the first trimester to 0.50 (95% CI: 0.45-0.55, p<0.001) and 0.39 (95% CI: 0.37-0.42, p<0.001) in the second trimester and to 0.49 (95% CI: 0.44-0.53, p=0.752) and 0.36 (95% CI: 0.35-0.38, p=0.037) in the third trimester, respectively. In parallel, PSV altered from 0.22 m/s (95% CI: 0.13-0.30 m/s) to 0.28 m/s (95% CI: 0.17-0.40 m/s, p=0.377) and to 0.25 m/s (95% CI: 0.20-0.30 m/s, p=0.560) in the three trimesters. In absence of second and third trimester Doppler data in complicated gestation, only a difference in PI was observed between complicated and healthy pregnancies during the first trimester (1.49 vs 0.80, p<0.001). Although individual studies have identified differences in PI between SpA located in the central part of the placental bed versus those located at its periphery, this meta-analysis could not confirm this (p=0.349).Conclusions: This review and meta-analysis concludes that an observed decrease of SpA PI and RI from the first towards the second trimester parallels the physiological trophoblast invasion converting SpA during early gestation, a process completed in the midst of the second trimester. Higher PI was found in SpA of complicated pregnancies compared to healthy pregnancies, possibly reflecting suboptimal utero-placental circulation. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for complicated pregnancies are yet to be carried out.

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“…Ischemic placental disease (IPD) represents various conditions of placental insufficiency, and each condition shares some common features such as a failure of spiral artery remodeling, uteroplacental underperfusion, chronic hypoxia, and placental ischemia . It is still under debate if an early failure of the spiral artery remodeling induces an overall change in placental blood flow and downstream resistance . However, it is reported that the local placental blood flow should decrease to ~10 cm/s to ensure adequate perfusion of oxygen and nutrition from the intervillus space to the villus .…”

mentioning

confidence: 99%

“…12 It is still under debate if an early failure of the spiral artery remodeling induces an overall change in placental blood flow and downstream resistance. [13][14][15][16] However, it is reported that the local placental blood flow should decrease tõ 10 cm/s to ensure adequate perfusion of oxygen and nutrition from the intervillus space to the villus. 17,18 Therefore, noninvasive real-time measurement of the volumetric placental blood flow may provide useful information in predicting IPD.…”

mentioning

confidence: 99%

Human Placenta Blood Flow During Early Gestation With Pseudocontinuous Arterial Spin Labeling MRI

Liu

Shao

Danyalov

et al. 2019

Magnetic Resonance Imaging

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Background Noninvasive measurement of placental blood flow is the major technical challenge for predicting ischemic placenta (IPD). Pseudocontinuous arterial spin labeling (pCASL) MRI was recently shown to be promising, but the potential value in predicting the subsequence development of IPD is not known. Purpose To derive global and regional placental blood flow parameters from longitudinal measurements of pCASL MRI and to assess the associations between perfusion‐related parameters and IPD. Study Type Prospective. Population Eighty‐four women completed two pCASL MRI scans (first; 14–18 weeks and second; 19–24 weeks) from prospectively recruited 118 subjects. A total of 69 subjects were included for the analysis, of which 15 subjects developed IPD. Field Strength/Sequence 3T/T2‐weighted half‐Fourier single‐shot turbo spin‐echo (HASTE) and pCASL. Assessment Four perfusion‐related parameters in the placenta were derived: placenta volume, placental blood flow (PBF), high PBF (hPBF), and relative hPBF. The longitudinal changes of the parameters and their association with IPD were tested after being normalizing to the 16th and 20th weeks of gestation. Statistical Tests Comparisons between two gestational ages within subjects were performed using the paired Wilcoxon tests, and comparisons between normal and IPD groups were performed using the unpaired Wilcoxon tests. Results The difference between the first and second MRI scans was statistically significant for volume (156.6 cm3 vs. 269.7 cm3, P < 0.001) and PBF (104.9 ml/100g/min vs. 111.3 ml/100g/min, P = 0.02) for normal subjects, indicating an increase in pregnancy with advancing gestation. Of the parameters tested, the difference between the normal and IPD subjects was most pronounced in hPBF (278.1 ml/100g/min vs. 180.7 ml/100g/min, P < 0.001) and relative hPBF (259.1% vs. 183.2%, P < 0.001) at 16 weeks. Data Conclusion The high perfusion‐related image parameters for IPD were significantly decreased from normal pregnancy at 14–18 weeks of gestation. Level of Evidence 2 Technical Efficacy Stage 1 J. Magn. Reson. Imaging 2020;51:1247–1257.

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Longitudinal Doppler sonographic measurements of vascular impedance in the central and peripheral spiral arteries throughout pregnancy

Cited by 16 publications

References 11 publications

Rheological and Physiological Consequences of Conversion of the Maternal Spiral Arteries for Uteroplacental Blood Flow during Human Pregnancy

Rheological and Physiological Consequences of Conversion of the Maternal Spiral Arteries for Uteroplacental Blood Flow during Human Pregnancy

Spiral artery blood flow during pregnancy: a systematic review and meta-analysis.

Human Placenta Blood Flow During Early Gestation With Pseudocontinuous Arterial Spin Labeling MRI

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